CHICAGO — A federal judge in Chicago says a city ordinance prohibiting the posting of commercial advertisements on lampposts and other public objects is too vague and therefore unconstitutional.

The Chicago Daily Law Bulletin reports Monday the ruling came in a lawsuit brought by RCP Publications Inc. RCP publishes a weekly paper of the Revolutionary Communist Party USA.

An apparent supporter posted a notice about RCP showing a movie. RCP was held responsible under the ordinance and ordered to pay a $350 fine.

Judge Matthew Kennelly says the lack of an adequate definition of “a commercial advertisement” in the city law allowed officials to arbitrarily ticket groups linked to unpopular causes and overlook violations by others.

A Chicago legal department spokesman says the city was “disappointed” and is “evaluating” its legal options.

Information from: Chicago Daily Law Bulletin ,